Naive? This is a proof of concept, and it makes people feel cooler. Dehumidifiers use significantly less power than cooling. The peltier they're using with a 30% duty cycle would require about 30W per person.
Dehumidify a typical room: 500W
Cooling a typical room: 2000W
Dehumidify a typical room: 500W Cooling a typical room: 2000W